Shark Activity for May 2010

The return of Nemo!
As we get in to May we are consistently having trips were we are viewing on average more than 10 different great whites per trip. Over the years some of our sharks have been given names that help us identify them when they arrive at the boat. The Great White Shark is nomadic therefore they are not residential, whenever a shark migrates out of the area we always hope that we will get to see it again someday and that it has not fell foul of the hooks and nets that man has placed in the ocean. On the 4th of May a shark which was last seen on the 20th October 2009 in the inshore area called Jouberts Dam “Nemo” returned to our boat alive and well. As soon as we spotted her distinct rolled dorsal fin and the missing right pectoral fin at the Geldsteen area a wave of excitement passed through the crew, “Hey it’s NEMO!!!”At around 2.6 M this little female continues to grow and doesn’t seem to be significantly disadvantaged in her ability to manoeuvre through the water. She has so far been spotted around the Geldsteen area near shark alley and also around the channel mouth area. Her behaviour is like that of the majority of our sharks. Nemo is calm, curious and inquisitive often taking more of an interest in the cage or the boat than the roped tuna line bait in the water. Nemo was last seen on 29/05/2010 on our afternoon trip. It was a beautiful clear winter’s day and Nemo was on form, twice in quick succession she popped up right next to the cage from under the boat and then moved very slowly to the bow of the boat with her head out of the water. A behaviour referred to as “spy hopping”, checking out the boat and the clients. Spy hopping behaviour more than likely evolved as a result of the Great White Shark observing pinniped (i.e. seal) haul outs. The Great white Shark has phenomenal eye sight that it is able to use both in and out of the water. Within the eye rod cells and cone cells are present, guess which other species else has these cells? You’re using them right now to read this, yes that’s right humans. That means as Nemo was spy hopping moving along side our boat she was viewing her environment (and the clients) in colour! Another misconception about Great Whites coined from the movie Jaws is that they have “eyes as black as coal”. If you are ever privileged enough to see a great White’s eye the pupil may be black but the iris is the most amazing and beautiful magenta-blue colour that you will ever see. When captured in the right light it is breathtaking!
No sea days!
From the 5th of May to the 16th of May we were unable to go to sea. We had 3 cold fronts pass through the area in that we work in, high wind speeds, rain and large swells that were on some days in excess of 8m. This meant that any scheduled trips were cancelled immediately. Our highly professional and experienced skippers will cancel if they feel that clients and the crew’s health and safety would be compromised by going to sea. We can always reschedule bookings so that you can come and view the beautiful Great Whites when it is safe to do so.



Back to sea!
On the 17th May we returned to sea! The cold fronts had passed and swells had calmed, and we have had clear sunny weather, it made a welcome change from the howling winds and rain that we were subjected to. We are viewing whales with increasing frequency on our trips; all three species have been spotted during May. On the 17th as we headed over to the Geldsteen area a Bryde’s Whale was spotted 50m off the port side. Bryde’s whales can grow up to 17m and weigh as much as 41 tonnes, as we continued our journey the Bryde’s whale broke the surface allowing us to see its distinct dorsal fin which is located ¾ of the way down its body and resembles a similar shape as a dolphin dorsal. We have also observed small numbers of southern right whales and humpbacks in the area, no doubt as we move into June these sighting will increase. Last year in June 2009 a group of clients were able to observe 3 Great White Sharks all around 3m in length from the cage, then to make their trip unforgettable behind the 3 sharks a humpback and her calf passed by giving them an amazing spectacle.
During our trip on the 17th we had good visibility and 11 different sharks visited the boat (including Nemo). Whilst chumming we could see one shape in the water coming up from the depths that was definitely not a shark, but it was staying deep. Eventually it came closer to the surface and revealed itself to be a short tailed stingray with a diameter of around 2m! The stingray came up to investigate the chum trail but quickly changed its mind after it saw the competition. The sharks didn’t attempt to predate upon the stingray keeping a distance of at least 3 meters until the stingray descended back to the ocean floor. After we had finished our trip we made a pass though shark alley to see the seals on Geyser Rock. In the summer months the seals will happily come along side the boat, during winter time however they know the Great Whites are patrolling close by and hug the shore very closely. We were able to observe 2 Great Whites naturally patrolling shark alley looking for a potential meal. Not all predation attempts are successful; a good analogy for the blubber that surrounds the cape fur seal would be that of a thick coat. During some attacks the Great White is unable to get a good grip of the seal and the seal is able to struggle free and make its way back to Geyser Rock and back to safety. We observed a large seal that had managed to survive an attack. Though the wound looks severe and chronic the damage inflicted is superficial, on the flip side the Great Whites is sometimes on the receiving end of defensive attacks from seals. It is not uncommon for us to observe Great Whites with deep scratches around their eyes and bite marks that have clearly been inflicted by the seals!

During our trip on the 19th we observed an unusual conspecies interaction at the Geldsteen area. The Great White Shark has so many highly tuned senses that what took place almost defies belief. Two females one +/- 2.7m and one +/- 3.0m both approached the bait from opposite directions. As the bait was removed the two sharks which had both been behaving very calmly the whole trip continued slowly towards each other and collided. It was more of a delicate bump than a big impact, upon this taking place the sharks very calmly moved away from each other in opposite directions. At the risk of making an anthropomorphic comment (attributing human behaviour to something non human) it was almost as if the two sharks had bumped into each other and apologised before going their separate ways. As evidence for this we were lucky enough to have one of our White Shark Project volunteers James Green from London in the cage when the incident took place. He was able to get a fantastic shot of the two sharks bumping into each other! Nice one James!
On the 23rd we were reminded that not all conspecies interactions result in an amicable ending. Generally the behaviour we observe with sharks is that they utilise mutual personal spacing i.e. they have an area of space around them that they will defend vigorously and if necessary aggressively. The Great White like other shark species will go to great lengths to signal to other sharks that enter its personal space that it is uncomfortable. Pectoral fins may be pointed straight down, the shark may gape showing its teeth to the shark that has entered its personal space. All of this is done to communicate to the other shark to move away. In most cases this works as we do not observe a great number of white sharks with bite wounds that have been inflicted by other white sharks. On the 21st however we were able to photograph a 3.1m female that had a bite inflicted upon her right hand side around the gill area. The bite has resulted in gill filaments being exposed on the 1st and 2nd gill slits. Once again our volunteer James was in the right place at the right time and was able to capture the photograph from the cage!
On another trip within the last week we were able to view a “bird bashing” event. We had been working at the Geldsteen area and several sharks had stayed with us for the whole trip when a Cape Gannet (Morus capensis) landed and decided that it would like to pick up a few small pieces of tuna that were floating down in our chum line. Landing in a chum line is not a good idea, especially when you have inquisitive white sharks around! To start with the 3 sharks didn’t approach the cape gannet, keeping a distance, but after a couple of unsuccessful attempts at the roped tuna bait that we had in the water the shark decided that it would try a different target, one that was gannet shaped. On the 1st and 2nd passes a male great white of around 2.5m in length circled closely from underneath and bumped the gannet twice, the gannet didn’t take the hint. On the 3rd pass the white shark decided to investigate the object using its mouth and it mouthed the gannet. The Great White has highly sensitive taste buds in its mouth and on tasting a mouth full of feathers it decided to spit the gannet back out of its mouth. The gannet then looking rather dishevelled and confused as to what had just happened finally made a good decision and tried to fly away. The same shark returned to the gannet and bumped it again twice before the bird was able to take flight. Again we had one of our volunteers in the right place to capture the action Joshua Peck from the Falklands was able to capture these amazing shots.

Summer Sharks!

This year has according to both skippers been the best February that we have ever had. Every trip has resulted in us seeing multiple sharks in the Jouberts Dam area opposite Pearly Beach. One trip that sticks out in mind involved a 3.5m female doing a full vertical breech 20 meters off the stern for absolutely no reason!! There were no prey items in the area, our visual target (the bait) and chum line which creates the artificial scavenging scenario for the shark was moving away from the boat in an SE direction. Given the fact that we were only in 10m depth of water the shark must have been doing in excess of 45kph the launch itself vertically straight out of the water (thanks goes to Mary one of our white shark projects volunteers who has graduated in physics for this estimate). Only a privileged few saw this spectacle (ah the benefits of getting involved with chumming!), the white underbelly gleaming in the bright sunshine was an awesome sight to behold! It also acts as a stark reminder of how beautiful and powerful these animals are.
This month has also seen some unusual environmental conditions, the water has been as warm as 21 C (the average temperature this time of year is normally between 9-14 C), and on some days the visibility has been nigh on perfect enabling those on board to see to the sandy bottom of Jouberts dam. The warmer water temperatures have resulted in the sharks being more active, and more willing to expend energy chasing the bait. One shark in particular called “Mickey” due to the pattern he has on his dorsal fin seems to relish the opportunity to rush the bait from deep, and on one occasion the bait line had been thrown out for the first time on an afternoon trip and before the bait handler had time to reach down to pick up the rope Mickey had the tuna head in his mouth and didn’t intend to let go!
We have also seen on two occasions the chum line attracting another great marine predator in this area a little lower down the food chain, that predator being the cape fur sea. We had two good working sharks both females and around 3M in length that had stayed around the boat for over an hour when the seal appeared. It swam towards the boat investigating the source of the chum, anticipation grew on the boat with everyone expecting the shark to burst from the depths and predate on the seal. Instead the seal came close to the boat and then it left without incident. The two sharks then reappeared 5 minutes later, given the sharks array of senses there is no doubt that the shark knew the seal was present (and vice versa) but chose not to attempt an attack. On another occasion a seal not only popped up in the chum line and swam to the boat but decided the tuna head on the bait line looked like quite a tempting free snack. The seal proceeded to attach itself to the tuna head and began to chew it!! Once again the seal left without incident despite there being sharks in the vicinity that we had been lucky enough to see on a regular basis. Who knows what amazing sights we will be privileged to on our next trip!!

WHITE SHARK PROJECTS RECYCLE SWOP-SHOP

The WHITE SHARK PROJECTS Recycle Swop-Shop in Masakhane is now in operation for 2 years – and is still going from strength to strength.

The Recycle Swop Shop was initiated by White Shark Projects in December 20 as an empowerment initiative for children in Gansbaai, and the aim was:

- To clean up the community and teach environmental awareness
- To teach children trading skills
- To teach children the value of working for something
- Help provide basic school supplies to children

The local community has hugely bought into the Swop Shop concept, a local retired 07lady, Nellie Moolman, volunteers her time on Tuesdays to assist with the running of the operation. She also initiated the Soup Kitchen last winter. Veronica Msopi – an assistant at the Swop-Shop – says: “I like to work at the Swop-Shop because it really helps the children. They are maybe in need of soap, pencils or just needs to have a cup of soup.


The Recycle Swop-Shop are also bridging a gap between different cultures. Volunteers from overseas that are part of the White Shark Projects Volunteer Shark Programme are assisting at the Recycle Swop-Shop on Tuesdays. For them its truly a touching and culturally enriching experience!

Comments from some volunteers:
“My first swop-shop experience was such a humbling one. It was good to see such a great community project. To see their faces when coming out of the shop… its priceless, such a small thing can mean so much” James Watters – Australia

“I saw a child’s face light up at receiving a pencil once a week whereas a kid back home would turn their noses up at something that doesn’t take batteries. There are also good kids. I saw one little boy pick a packet of ten sweets for his recycling and he gave nine of them away before eating one himself, and other kids sharing their toys and stationary with the ones that didn’t have any recycling this week…”
Dan Hunte - UK

“The Swop Shop really opened my eyes to a need that I was not aware of – the children are so eager to participate and do something! I found being a part of this, even if it was just sorting litter, did change not only my perceptive, but surely my value system too…” Mark Easton - UK

Some interesting facts about the Recycle Swop-Shop is as follows: In 2009 the children of Masakhane brought over 12 tons of recycables to the shop. In the first 2 months of 2010 – with only 5 shop days – they already brought more than 1,5 tons to the shop. This is absolutely great news!

However, the Swop Shop is completely dependant on donations to operate. Donations from all kinds are welcome: from shoes and clothing, to pencils and toothbrushes.

For all at White Shark Projects and associated with the Recycle Swop-Shop – this initiative is really an eye-opener that lies in the responsibility that the children are taking in cleaning up their community; and in the same instance promoting recycling habits.

Shark Facts by White Shark Projects Team

The great white we've come to know

Great white ID

Quite simply, great whites are grey on top with a white underbelly – for perfect camouflage from above and below. The white belly blends in with the sky and the dark back blends in with the rocks below.

Great white addresses

Great whites swim the oceans of the world. Concentrations, or 'hot spots', are found in the temperate waters of south-western Australia, South Africa, California and Mexico. The densest known population is right here, around Dyer Island, South Africa!

They are pelagic fish. That means they prefer the upper layers of the sea, but also venture down to 1 280m. They are mostly seen in coastal waters where the pickings are rich. Seals, whales, dolphins, other sharks and large bony fish make a good shark diet.

We've recently realised that great whites spend a lot of time in the open ocean too. When 'Nicole', a female great white, was tracked to Australia and back, we learned so much more about their migration and behaviour. In fact, great whites have the longest recorded migratory range of any marine creature. Nicole covered a staggering 22 000km from Dyer Island (South Africa) to western Australian and back in just under nine months! Her average swimming speed was 4.7km/hr. She spent 60% of her time in the top 5m of water, 20% in the area below that and 20% down at her maximum depth of 980m.

Favourite foods

The white shark is an apex predator – right at the top of the feeding pyramid – and is vital to a healthy marine ecology. The only animals who attack them are other great whites, sperm whales and orcas.

These apex predators take their pick of the buffet, choosing fish, smaller sharks, turtles, dolphins, seals and sea lions – or even the blubber of dead whales.

Great whites are partly warm-blooded. Most of their body is kept at 14°C above the temperature of the surrounding water. They are economical with their calories and can go for weeks between meals. With one bite, great whites gobble about 14kg of flesh, and can gorge on several hundred kilograms of food. Do they like the taste of humans? Well, humans are not exactly healthy for a great white because its digestion is too slow to cope with the human body’s high ratio of bone to muscle and fat...

Vital statistics

Great whites of up to 7m (21ft) long have been reliably reported, but their average length is around 6m (18ft). They're over a metre long at birth (3 to 5ft).

No one really knows how long great whites live. It's hard to find out because they lead lonely lives and are so migratory. Research in recent years should bring us closer to knowing.

Power-sensing!

Great whites have powerful sensing mechanisms – a mega sense of 'smell' and an ability to sense the electrical fields radiating from living creatures.

They 'breathe' via gills, so nostrils are solely for sniffing out prey. Each nostril is divided in two, separating the water into two flows, one incoming and one outgoing. The water flows over sensory organs covered with millions of olfactory cells connected to the 'smelling' centre of the brain. The great white is one big swimming nose!

They hunt down prey with an unusual electrical field detection system. Minute capsules filled with a gel-like substance are sensitive to electrical discharges as small as .005 microvolts! Sensory cells pick up these signals and transmit the information to the brain. All marine creatures generate small electrical fields – where their skin meets the water, from the mucous membranes in the mouth and gills of fish, or from the blood of wounded animals. The great white 'reads' the signals and decides who's swimming normally, who's panicking, or who is incapacitated.

A sharky grin

When a great white attacks, it thrusts its jaw forward. This makes for the widest possible grab and lets teeth grasp the prey.

Sharks' teeth change over time depending on what they eat. Smaller sharks, less than 3m, generally eat fish. These young sharks have pointed teeth so that their jaws can pin prey. As they get bigger, they start to add larger prey such as seals and dolphins. To dismember such big animals, their top teeth become stronger, serrated and triangulated. The lower teeth stay pointed so that the shark can still pin the prey.

What's with the eyes?

Much like human eyes, shark eyes have a light-sensitive layer at the back called the retina. A shark's retina has millions of microscopic rod cells helping the shark see in dim light.

In low light, shark eyes shine like a cat's. That's because the tapetum, a layer of shiny cells behind the retina, reflects light back through the eye helping them see even better in low light. In bright light the tapetum can be covered with dark cells to cut reflection and protect the retina.

Sharks have two eyelids to protect their eyes. Often the eyelids don't meet. Some sharks have a third eyelid (nictitating membrane) – useful protection when attacking prey. If there's no nictitating membrane they roll the eyeballs back under the true eyelids – and there's the white-eyed look.

Mystery and reproduction
Male great whites are ready to breed when they reach approx 3.8m long. Females are ready at approx 4.8m. Though they both have a hole near the pelvic fins called the cloaca, you can see the difference between male and female sharks.

Male sharks have modified pelvic fins called claspers. They also have two muscular sacs in their abdominal wall which they fill with seawater. Internally males have testes that produce sperm and secrete male hormones.

Female sharks are mostly bigger than male sharks. Other than that, they look the same, except they don't have claspers. Inside, they have a pair of ovaries where female hormones and eggs are made – interestingly, usually only the right ovary makes eggs.

We know almost nothing about how and where great whites mate. Some believe that making a large kill has a soporific effect on them that may lead to mating.

We have never seen a great white give birth, though we know they are ovoviviparous. That means the eggs grow inside the female, hatch there and carry on growing until they are born between spring and summer. They give birth to between 4 and 14 pups and may have only 4 to 6 litters in a lifetime. At birth, the pups are about 1.5m long and are already able hunters. They grow quickly, reaching 2m after their first year of life.

White shark titbits

White sharks store extra fat in two large livers and draw on these stores when times are hard. The livers help to keep the shark buoyant.

The dorsal fin is flexible (bendy) and works with the tail to make the shark agile.

The dorsal fin is as individual as a fingerprint – the trailing edge and the arrangement of notches in the fin is unique.

The great white is the only apex predator that hasn't been kept successfully in captivity. Where it's been tried, the sharks were released due to stress.

Conservation: It's tough at the top

Being at the top of the food pyramid means white sharks are vital to a balanced marine ecology. They control the populations of prey species and weed out the sick and wounded. A healthy ocean depends on a robust population of apex predators. Sadly, the survival of the great white is threatened by the ignorance and greed of humankind who continue needlessly to slaughter them. Responsible tourism promotes conservation, awareness and respect for the great white shark. We work towards sustainable populations of great whites in the waters of the world.

For more information on these incredible animals, visit www.whitesharkprojects.co.za